Portion of an electronic mouse



FIG. 1 is a front perspective view of portion of an electronic mouse showing my new design;

FIG. 2 is a top view thereof;

FIG. 3 is a right side view thereof; and,

FIG. 4 is a front view thereof.

The broken line showing of various regions, including the unshaded areas therein, is for illustrative purposes and forms no part of the claimed design. The difference in shading indicates a contrast of appearance and does not depict any particular color, texture, or material. 

The ornamental design for a portion of an electronic mouse, as shown and described. 